One of China’s most high-profile millionaire Good Samaritans who adopted more than 100 orphans over the last two decades has been arrested over alleged “gang-related blackmail”.

Li Lijuan, 48, from Wuan in northern China’s Hebei province, was also charged with “disturbing social order”, and her bank account, holding more than 20 million yuan (US$3.1 million) and over US$20,000, was frozen, Shanghai-based news portal Thepaper.cn reported.

In addition, Li’s Love Village orphanage in Wuan was closed. The 74 children living there had been sent to hospitals for check-ups and would receive professional counselling, Wuan police said in a statement on Friday.

The statement did not elaborate on Li’s alleged gang-related activities.

“In response to the public tip-offs that some trafficked children had been adopted in [Wuan], police will collect blood samples and fingerprints from these children and add their details to the public security system’s register of missing children,” the statement said.

Wuan mayor Qiang Yanfeng said the children would move to state orphanages and their medical and education costs would be covered by the government, Thepaper.cn reported.

Li’s son, Han Wen, confirmed on Saturday night that his mother, who was in Beijing for cancer treatment, was arrested by Beijing police.

Her arrest came two weeks after Wuan authorities claimed on April 21 that Li, who made a fortune from iron ore mines to become the city’s richest woman, had breached civil affairs regulations by failing to register Love Village with the local civil affairs administration since 2014.

News portal Jiemian.com earlier quoted Li as saying that she did not register the orphanage because she was told that the local government was doing away with some approvals to streamline bureaucracy.

Li’s daughter, Li Dan, said the allegations against her mother were ridiculous and the money in her mother’s bank account was compensation from a government takeover of the iron ore mines, Jiemian reported.

Li Dan confirmed that the Love Village children had been taken away by police, and the family would contest the charges.